New Linear Coordination Polymers Based on Copper(I) and 4,7-Phenanthroline: Structure Dependence on Solvent and Counteranion

Three new linear coordination polymers containing Cu(I) and 4,7-phenanthroline (phen) have been synthesized and structurally characterized by single-crystal X-ray diffraction. [Cu(phen)(MeCN)2]PF6 (3) and [Cu(phen)(MeCN)]BF4 (4) are prepared from acetonitrile, and [Cu(phen)(BzCN)]BF4 (5) is made from benzonitrile (MeCN = acetonitrile; BzCN = benzonitrile). All of the compounds have linear polymeric structures containing Cu(I) centers coordinated by two bridging 4,7-phenanthroline ligands, with additional coordinated solvent molecules completing the copper coordination sphere. In 3 and 4, when acetonitrile is used, two and one MeCN solvent molecules coordinate to each Cu atom, resulting in a distorted tetrahedral and distorted trigonal geometry, respectively. The major interchain interactions are phenanthroline π−π stacks. When benzonitrile is used in 5, the chain-packing motif changes to allow the coordinated benzonitrile ligands to participate in the interchain π−π stacking. Crystal data: for [Cu(phen)(MeCN)2]PF6 (3), monoclinic, space group P21/c (No. 14), with a = 11.4303(6) Å, b = 11.4954(6) Å, c = 14.0444(7) Å, β = 99.948(1)°, and Z = 4; for [Cu(phen)(MeCN)]BF4 (4), monoclinic, space group P21/c (No. 14), with a = 8.7677(5) Å, b = 11.5140(7) Å, c = 14.8858(9) Å, β = 96.548(1)°, and Z = 4; for [Cu(phen)(BzCN)]22BF4 (5), triclinic, space group P1̄ (No. 2), with a = 11.338(1) Å, b = 12.461(1) Å, c = 13.904(1) Å, α = 115.909(2)°, β = 100.870(2)°, γ = 92.052(2)°, and Z = 2.